BEIRUT (Reuters) – Syrian rebels besieged in the outskirts of Damascus say they are facing a slow but steady advance by President Bashar al-Assadâ€™s forces, and are pinning their hopes on an anticipated influx of weapons from the Jordanian border.

Opposition fighters once threatened Assadâ€™s dominance of Damascus but are now struggling to repel his forces, who have been emboldened by winning a strategic border town further north and have help from Lebanese Hezbollah militants and Shiâ€™ite Iraqi fighters.

â€œThe regimeâ€™s goal is to slowly bleed us until we are forced to surrender. They are advancing slowly to preserve their fighting force,â€ said Amran, an activist speaking by Skype from the ring of suburbs known as the Eastern Ghouta.

Rebel prospects for reversing Assadâ€™s gains in Damascus may now hinge on military support from Western and Arab backers.

â€œWe can survive for a long time, because our fighters know the terrain, but until we get weapons we cannot repel the advance,â€ Amran said.

The rebels believe a recent U.S. decision to give them military support will re-open an arms pipeline from Jordan that was shut down as the United States and Russia negotiated a planned â€œGeneva 2â€ peace conference.

But this weekâ€™s G8 meeting saw no narrowing of the differences between Moscow, Assadâ€™s main arms supplier, and Washington, which wants Assad to step down in any transition. Despite Washingtonâ€™s reluctance to define what kind of help it is willing to give, the mostly Sunni Muslim rebels expect Sunni-ruled Saudi Arabia to step up support to help them fight Assad. He is backed by Riyadhâ€™s regional Shiâ€™ite rival Iran in a two-year conflict that has become increasingly regionalized.

â€œWe had several meetings in Jordan and Ankara and discussed opening the weapons pipeline to the Damascus rebels from Jordan. I expect good news soon … We will be getting advanced weaponry but I cannot say what kind,â€ said Abu Moaz al-Agha, a spokesman and commander from the Ansar al-Islam brigades in Damascus.

Rebels want anti-tank and anti-aircraft weapons to challenge the dominance of Assadâ€™s air force, which has allowed him to keep rebels on the defensive even in their own territories through daily air strikes.

â€œWe still need time to plan out the system for delivering the weapons. But I am hoping that within 30 days there will be changes on the ground,â€ Agha said, speaking by Skype.

Over the past two months, rebels around Damascus lost nearly all their supply lines and are struggling to get enough food, let alone weapons, into the eastern and southern outskirts of the capital.

There has been a slow increase in weapons supplies in recent days, particularly to the north, where Assadâ€™s forces are also planning a slow encroachment on rebel strongholds in Aleppo.

WAITING FOR REBEL SUPPORT

As well as getting arms over the southern border, the Damascus rebels need opposition forces in neighboring Deraa province to alleviate the blockade from outside.

â€œWe are trapped inside al-Ghouta and there is absolutely no route into the area if the mujahideen (holy warriors) in the south do not come to open the front,â€ said activist Amran.

But infighting and rivalries have long plagued the rebels – it is what made Western powers hesitant to back their fractious forces and has also sabotaged many rebel efforts to unite against Assad offensives across the country.

In the Ghouta region, mistrust and greed has prevented fighters blocking advances as they await help, some rebels say.

â€œThe regime is advancing on the Marj area and has taken several towns in a critical part of the rebel base here. Unfortunately the blame for this lies on us as much as them,â€ said a fighter speaking by Skype, who asked not to be named.

â€œSome of the biggest brigades here are focusing on cementing their control on specific towns, to loot factories and seize all the supplies. Theyâ€™ve ignored the wider cause,â€ he said.

Assadâ€™s forces are also advancing on the Sayyeda Zainab district, which houses an important Shiâ€™ite shrine and has been used as a rallying call for Shiâ€™ite fighters.

Syriaâ€™s conflict has killed more than 93,000 people and has descended from a popular protest movement against four decades of Assaf family rule into a civil war with sectarian overtones.

The countryâ€™s Sunni majority and has enjoyed rising but inconsistent support from Sunni countries, including a flow of radical Islamist fighters. Assad has relied on minorities, particularly his Alawite sect, an offshoot of Shiâ€™ite Islam, and a staunchly loyal support system from Hezbollah and Iran.

An activist working with the rebels in Damascus said that while he believed the rebels had a good chance of holding out until a weapons pipeline was made from Jordan, the chance of seizing Sayyeda Zainab has likely been lost.

â€œOur own men here betrayed the cause,â€ he said. â€œNow our only help is our brothers from outside.â€